Bevel-gear



rATENT oFFI-cs.

'BANDAL E. TALLEY,l or IRWIN, PENNSYLVANIA, AssIeNoa rro WEsTINeHoU'sE smc- TRIC & MANUFACTURING COMPANY, A CORPORATION o F PENNSYLVANIA.

BEVELGEAR.

Specification of Letters Patent.

Patented June 1, 1920.

Application filed July 5, 1919. Serial No. 308,741.

To all 'whom 'it may concern.'

Be it known that I, RANDAL E. TALLEY, a citizen of the United States, and a resident of Irwin, in the county of Westmoreland and State of Pennsylvania, have invented a new and useful Improvement in Bevel- Gears, of whichfthe following is a specification.

My invention relates to gear wheelsand, more particularly, to bevel gears and pinions and it has, for its primary object, the provision of a molded, composite, bevel gear of improved construction and superior strength. f .v

. Heretofore, gear wheels have been formed of superimposed layers of brous sheet material, such as paper or duck, impregnated withx a heat hardened binder such as a phenolic 'condensation product. In manufacturing such gears, the layers of sheet material are disposed in planes at right angles to the axis of the gear to be formed and the assembled material 'is generally cured and hardened in the form of plates or blanks from which gears are subsequently cut.

Spur gears and the like cut from plates of this characterare unusually strong, durable and silent in operationand have been found tobe very satisfactory, as cutting spur teeth in the periphery of a gear blank of such material provides teeth in which the working faces are comprised of edges of the sheet material so that the strain exerted upon the teeth is exerted against the edges of the several layers constituting the gearv body. y v

It has been found, however, that bevel gears constructed from plates or blanks of superimposed layers of fibrous sheet material and a hardened binder are not so satisfactory as the end thrust transmitted to them by a meshing gear/ or pinion acts, not lagainst the edges of the laminations, but rather against the faces thereof and, com sequently, tends to separate the several lay- Because of this, it has been necessary either to employ shrouds or to limit the face angle of gears of this char-- acter to about 30.

The primary object of my present invention resides in providing a bevel gear, ofl laminated non-metallic material having a self-supporting working body, of such char-A acter as to permit cutting of the teeth at any desired angle without necessitating the employment. of shrouds or other supporting means. x A

In the drawings, Figure 1 is a diametral sectional view of a bevel'gear of a laminated non-metallic material as they are usually constructed; Fig. 2 isa corresponding View of a similar gear constructed in accordance cey with my invention and Fig. 3 is a similar View of my gear with a metal hub.

It has been common practice, in the past, to impregnate suitable fibrous sheet material, such as duck or paper, with a suitable binder such as shellac, copal or other varnish gum or gum resins, but preferably with a binder such as a phenolic condensation product, and to superimpose the sheet material so treated and to subject, it to heat and pressure to compact it and harden its binderg'to' form a laminated non-metallic plate which is hard and unaffected by moisture, oils and the like. Gear blanks have been cut from fsuch plates and gears have been machined sheet material suchv as duck or paper, impregnated with and bound together by, a j

hardened binder such as a phenolic condensation roduct. As here shown, the teeth 3 cut 1n the periphery of the gear are formed at an inclination toflthe several laminations or layers comprising the gear body so that end thrust exerted against the layers, by a meshing gearvor pinion, is appliedl in a direction tending to force apart or separate the various layers. Because of this, `a gear of this character must have its face'angle limited to about 30",I or it must be reinforced by shrouds.

According to my present invention, I may superimpose properly impregnated sheet material in the same manner as has been previously done and before subjecting it to heat and pressure, I may cut from it annular or circular gear blanks of the desired dimensions. The gear blanks thus provided may then be cured in molds of suitable construction to cause a vdishing of the blanks and consequentlyof the layers comprising it. By providing molds with working faces of various degrees of curvature it is possible to cause such dishing of the molded blanks as will bring the peripheral edge portions of the layers or laminations comprisingthe blanks at substantially right angles to the plane at which the teeth are to be cut.

It will, of course, be understood that during this molding or dishing of the blanks,

they are not only subjected to pressure but also to heat so that the binder is transformed to its hard, strong, and substantially insoluble condition. After the blanks have thus been cured the'teeth may be cut in the usual or any preferred manner.

Obviously, in place of cutting gear blanks from a stack of suitably treated sheet material, the blanks may be punched or otherwise cut from a single-impregnated sheet and a suitable number of the layers thus provided may be superimposed to provide a gear body ofthe desired thickness, when cured. y

In Fig. 2 I have illustrated a bevel gear 4 constructed in accordance with my invention, in which the dishing or curving ofthe several layers or l-aminations 5 is clearly indicated. As here shown, the portions of the laminations forming the teeth 6 are disposed at substantially right angles to the faces of the teeth so that the end thrust exerted against the gear is directed against the edges of the several layers or laminations, as is the case in the ordinary spur gear of this character, and does not act or tend, in any way, to separate the layers. 1

Becase of this, bevel gears 4constructed in accordance with my invention are much strongerthan those previously formed of similar material, the face angles of their teeth are in no way limited and the employment of shrouds is rendered unnecessary.

If desired, a gear ring 7 may be molded .upon a metal hub 8 as shown in Fig. 3,'the

ring being dished or bent during the curing of the binder. v

Although I have described my invention in considerable detail, both as regards the materials employed and the manner of as peripheral edge portions of the sheets being bent to dispose them at substantially right angles to the face of the gear teeth.

2. A bevel gear or pinion'comprising a body of superimposed layers of fibrous sheet material and a binder, the sheets being bent to provide an outwardly fiaring peripheral flange and teeth cut in the edge of the flange.

3. A bevel gear or pinion comprising superimposed layers of fibrous sheet material and a heat hardened binder, the edge por-Y tions ofthe layers being bent to provide an outwardly flaring peripheral flange and teeth cut in the ange. l

4. A bevel gear or pinion comprising superi'mposed layers of fibrous sheet material` and a binder molded thereon, the sheets being bent to provide an outwardly flaring peripheral flange in which the teeth are cut.

6. A gear blank for forming bevel gears or pinions comprising a body formed with an outwardly flaring peripheral fiange, the body being composed of superimposed layers of fibrous sheet material and a hardened binder withthe edge portions of the sheets and projecting into and forming the flange.

7. A bevel gear or pinion comprising a body of superimposed layers of fibrous sheet material and a hardened binder, the edge portions of the layers being bent to providel a peripheral ange and teethl cut in the flange. P i

8. The method of forming a -bevel gear or pinion blank which `comprises superlmposing layers of fibrous sheet material impregnated with a phenolic condensation product to provide a planiform body, bending portions of the sheets to create anl outwardly flaring peripheral flangeupon the body and subjecting the body to heat and pressure while the sheets are thus bent to compact it and harden the binder.

9. vA method of forming a bevel gear'or pinion which comprises superimposing layers of fibrous sheet material associated with a binder to provide a planiform body,bend

eral flange about the body, treating the body to compact it and harden the binder and cut ting teeth in the flange.

In testimonyl whereof, I have hereunto subscribed my name this 24th 1919.

RANDAL E. TALLEY,

day of June 115. ing portions of the sheets to create a periph- 

